


A Sharp Incline

by skerb



Category: Undertale (Video Game)
Genre: Come Marking, Crosstale Sans/Dreamtale Sans | Dream (Undertale), Dreamtale Sans | Dream (Undertale), Ecto-Penis (Undertale), Ecto-Vagina (Undertale), Empathy, Hotdogging, Intercrural Sex, LV20 Cross, M/M, Semi-Public Sex, Sex Pollen, Size Difference, Size Kink, all horny sorry, needy cross, toxic positivity, utmv - Freeform
Language: English
Status: Completed
Published: 2020-11-26
Updated: 2020-11-26
Packaged: 2021-03-09 20:01:00
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,164
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27721808
Author URL: https://archiveofourown.org/users/skerb/pseuds/skerb
Summary: Cross, overburdened with LV, finds Dream irresistible. Dream finds Cross's new energy intoxicating, wrapping him up in positivity, warmth, and devotion. So when Cross slips behind him by the stairs, radiating hunger, Dream doesn't want to say no...
Relationships: Cream - Relationship, Sans/Sans (Undertale)
Comments: 14
Kudos: 188





	A Sharp Incline

**Author's Note:**

  * For [withtheworms](https://archiveofourown.org/users/withtheworms/gifts).



> Featuring wormy's LV20!Cross, the boy that fucks.

When Cross slips behind him around the banister, there’s no mistaking what’s about to happen.

Dream can feel it. It’s subtly different than the radiant positivity he feeds on. It’s high octane, hitting his senses like a freight train. It coils around his soul with gentle, eager fingertips, warming him, lighting him up. Involuntarily, a golden blush spreads over Dream’s cheekbones when he hears Cross’s voice husk out, low and eager next to his skull.

“I want yoủ̴̬͐.”

Cross’s voice echoes like waves on a settling pond in a room with a high ceiling, a weight to his words that demands attention. Similarly, Cross’s body leans into him. Dream drowns in the sudden burst of it, undammed and roaring in his head. It fully encompases him, amplified by his aura.

It’s _different._ It’s no gentle pool. Positivity doesn’t normally make him react this way, Cross’s devotion skimming across his very being like fingertips skating on an icy pond. He shivers when Cross’s arms loop around his chest, a gentle touch no matter how sharp or twisted his body’s become.

“Oh,” Dream breathes. It’s more of a shudder. Cross’s affectionate kiss makes prickles creep up the back of his spine. It kindles a small warmth where it lands, steadily heating up the more Cross’s feelings bleed into him.

It hits him like a heatwave. Cross is so needy, so eager to experience him. His love is boundless, surpasses any known ocean, spanning the skies into unknown fields of stars. His touch feels like the universe, cradling him, soothing him yet winding him up.

 _“Oh,”_ Dream gasps again. His hands feel useless, balled into loose fists in front of him. Cross barely touched him, but his intent is clear. Automatically, Dream raises his arms. The gesture could be taken as placating.

Cross has a way of making him feel enshrined and protected, cherished and worshipped. He’s never forced himself, not with his new disposition, and Cross would take cues if Dream decided to hunch into his fervent kisses to stave them off.

But he doesn’t. Cross’s fangs tickle at his cervical vertebrae, his aura tingling around them. It only amplifies his innate magic, setting it to coiling around the base of his spine.

“Do you want thi̷s̴?”

He feels Cross bump into his backside, a size that had presented worry to him upon their first handfuls of intimacy. Dream finds himself clenching on nothing, yearning for it as he’s brought closer to the wall hidden around the banister. Hastily, he makes an urgent sound low in his throat.

For all his pride, Cross is still a little shy to outright ask for what he wants. He whispers a sigh, hot and humid against Dream’s neck as his hand ventures towards the flare of Dream’s hip. It’s a delicious distraction, one that has a plea stuck in Dream’s throat.

“Can I̷..?”

Something within Dream’s soul floods out, Cross’s affections tender as he gently plucks at his leotard. Suddenly, being clothed has very little meaning right now, not when Dream wants to bathe entirely in Cross’s aura.

Dream gives a shaky little nod. He expects Cross to slice through the black fabric at the waist, but instead his hands rove under his tabard and over his ribs. His hands linger as though to savour every reaction as Cross gives Dream’s neck a tentative touch with the tip of his tongue.

The noise Dream makes is soft, yearning. Cross’s laugh is gentle but oh-so-satisfying. The tips of his fingers are sharp, dragging down Dream’s ribs to bite into bone, just a little. A gentle pulse of gratification slithers its way under Dream’s self-defense, rendering him to putty.

Still husky, Cross whispers against Dream’s neck, tasting him. “If you’ll have m̸e̴… will you give me gold, my ligḥ̵̌ͅt̷̗̥͐͋..?”

His breath gusts against Dream’s body, eliciting a sweet shiver when the pet name rolls off his tongue. Dream swallows some debauched noise stuck in his throat when he realises that Cross is asking for him to form his ecto. His magic is already warm and eager to please him, simmering under Cross’s palms.

He yearns to be served. Entranced. Cross makes him feel like a newborn star, so filled with light, energy, and radiance, that he wants to savour that sensation in his soul forever, to never let it escape. Dream’s breath catches on its next exhale as his magic pools effortlessly, his body slight and manageable even before Cross disappeared and came back. Now, Cross _overwhelms_ him, body and soul.

Cross’s sharp phalanges graze down the slopes of his sides, catching on the fabric as he pulls it down. He maps every part of him, his rough hands dextrous and lithe as they fully explore Dream’s narrow hips.

“Right now?” Dream murmurs, but it’s slightly slurred. It’s not that he doesn’t want this -- Dream adores Cross on every heavenly plain he’s got access to. Drunk on the magnitude that Cross’s power emits, there’s still a niggling worry that someone might stumble upon them unawares. _“Here..?”_

Insistently, Cross nudges him forward with his hips. Dream stumbles but puts an arm out against the wall to brace himself, his soul drumming up fiercely. Cross is pushy in a way that’s inviting, bold, like a beast unleashed but still too shy to take control until spoken to. Dream feels his fangs at his neck, the slight curve of Cross’s tusks press against his cervical processes. Wordlessly, Cross huffs at him, a noise that almost sounds impatient.

“Here,” Dream answers for him. His balance starts to waver when one of Cross’s femurs invades the space between his legs to part his trembling thighs. One of Cross’s hands ghost down Dream’s side again, taking the leotard with it. It snaps effortlessly from the small collar wrapped around Dream’s throat, possessivity and devotion radiating from Cross in a haze that makes Dream’s mind drift in unseen currents.

His body fills out a little more, golden hues shifting under the influence of Cross’s violet magic. It mingles together like oil and water, never mixing into a muddy mess, but swirling, coiling, fine to intermingle but never to become one.

They have ways of fixing that.

Dream turns his head to peek over his shoulder, magic high on his cheekbones as the hunger in Cross’s eyes turn on him.

He wants him.

The fabric shifts easily from Dream’s hips, gliding down his thighs to make room for Cross. His knight removes his leg from the base of his pelvis and Dream has to repress a groan of protest. He thinks about Cross’s size, how much their first tangled moments were for him. There’s an anticipatory throb that tugs somewhere within his soul.

Cross pushes forward. It’s unfortunate how much Dream likes it when Cross overtakes him, his warm hands grazing down his stomach. He takes his time as Dream’s vision starts to wash with violet, a haze of such intensity that he barely feels the need to protest when his leggings are pushed all the way down.

Cross moves him so easily, too. He loves to be surrounded by him, even now. As Dream is pulled against him, there’s a hasty movement behind his ass, of Cross pulling down the hem of his shorts with an audible sigh of relief.

Cross is huge. There’s something to be said about that, when Dream’s cunt ached for days following the first time they made love, but he still hesitates even now. Given no prep, even as eager as he is, it’ll do more than sting. It’ll hurt. He anticipates the quick and thorough fingering from Cross’s large fingers, spreading Dream open until his body quakes, but it never comes. Cross just moves him where he’s needed to be, sliding his massive length between Dream’s thighs with a barely bitten-off grunt.

The pain doesn’t come. Dream swallows at the drag along his slit, the warmth of Cross’s dick spreading his lips as he’s pushed back against Cross’s body. Dream feels every subtle shift of Cross’s magic intimately; the soft curves and the thick ridges of false skin that create a torturous texture. The filthy, desperate groan his knight pushes against his acoustic meatus thrums right down to his marrow, filling Dream with a desperate reverence he only feels from Cross.

He doesn’t push inside. Dream tentatively leans back, using the bulk of Cross’s body for something solid to ground him. He can’t quite close his legs like this, but that’s ok. He just lets the beat of Cross’s soul thrum against his back, his magic moving in short little bursts.

Dream gives an encouraging hum, wrenching his eyes shut. With just so little, Cross reaches down and glides his fingers down his conjured abdomen, closer and closer to where Dream’s spread open. Excitedly, Dream sucks in a sharp breath as large fingers slowly tease down his hood to encircle his clit, rubbing generous circles against it.

A shudder wracks through him, making Dream appreciate the arm slung around his stomach so he can cling to Cross even as he clenches down with pleasure. His hips move with the generous push, Cross’s length sliding back between his lips, moving in all the wet.

He uses him, just using the channel between his thighs to thrust into. Dream tightens down on nothing, on the pure sensory bliss of Cross’s fingers against his clit. It makes him hop a little, dragging lewd gasps from his teeth the rougher Cross goes. When he reopens his eyes and looks down, he sees the tip of Cross’s dick glisten with his fluid, precum starting to dribble the more he moves.

It feels unbelievable. His thighs part as Cross moves him, splayed out to find a sweet angle. It pushes across him, never into him, and Dream keens softly when he attempts to keep Cross against him by squeezing his thighs together. Gone are his worries that someone might hear him. Cross holds him close to keep, a steady input of pleasure and sweet intensity so raw and overwhelming.

There’s no doubt that he’ll break if he thrusts inside of him, but Cross seems content to grind against him, using the slippery gush of arousal to ease the way. Cross’s noises grunt out of him, almost pained, delirious on the sensation of Dream’s power. Of _Cross’s_ power, amplified in such a perverse way that Dream has trouble thinking straight.

The pleasure climbs. Dream scrabbles as he finds purchase, fumbling for a belt or a sleeve to cling to. He feels like something within his soul is overflowing, pooling down his spine and simultaneously wrapping around his throat. His choked off whimpers heighten when Cross moves him into a better position, Cross’s fingers wet on Dream’s stomach while his other hand pulls his thigh back, creating a torturously sweet friction that has stars dotting Dream’s vision.

Cross sounds feral, wrapped up in it. His aura hazes over Dream’s vision, spilling over his skull and into his eyes, filling him with his essence. He shudders when the tip of Cross’s dick glances past his cunt, dragging the fluid to rub along his thighs, winding him up.

He’s not going to last long. Cross’s thrusts speed up to a momentum that drags harsh moans from him, every inhale he gasps filling Dream’s skull like a cloying heat. He arches when he feels the pulse of Cross’s dick throb against him and Cross’s grip tighten on his body, the first blurts of cum smearing along his lips. He murmurs something barely audible, huffed against Dream’s head like a secret to the universe. In Dream’s soul, something leans hard, struck like a chord, a pendulum swung in just the right direction.

Dream clenches down at the next pass, abdomen tight and his back arching. He blindly grabs for Cross’s hood, fumbling, tangling his fingers into the thick fur of it as he gives it a fierce tug. He groans out his appreciation, drunk on lust, love, fealty, and worship. Cross fucks him past his orgasm until Dream’s body twists and he shouts out in blissed agony.

Cross needs this. Whether it’s due to the accumulation of LV, the twisted energy that makes up the majority of his magic, or the fact that Dream accepts him heart and soul, Dream doesn’t know. All he knows is that this is vastly different than their tentative firsts, where Cross would suffer and lock himself away instead of giving in and chancing to hurt Dream.

Now he seeks him out. Now Dream’s _needed_ beyond all else. He’s held in Cross’s strong arms, pressed tightly to his chest. Dream’s entire body throbs like a heartbeat, his mind frayed and blissed out. Spores of golden-orange bruises bloom up under Cross’s hands from where he held on too tightly.

Reverently, Cross presses soft kisses to the back of his skull, nuzzling him like Dream’s the best thing he’s ever known. He’s absolutely _taken,_ and he’d have nothing less than that.

**Author's Note:**

> Inspired by wormy's very nsfw art [that you can see here](https://twitter.com/weirdwormy/status/1330299381392822277?s=20) (18+ ONLY)


End file.
